Holding fixture for crystals



W. L. BOND HOLDING FIXTURE FOR CRYSTALS July 18, 1950 Filed July 9, 1948 2 Sheets-Sheet l FIG! INVENTO/P W. L. BOND mam A TTOPNEY 2 Sheets-Sheet 2 Filed July 9, 1948 INVEN TOR W L. BOND E2" A 7' TORNEV the crystal.

Patented July 18, 1950 HOLDING FIXTURE FOR CRYSTALS Walter L. Bond, Summit, N. J assignor to Bell Telephone Laboratories,

Incorporated, New

York, N. Y., a corporation of New York Application July 9, 1948, Serial No. 37,857

This invention relates to holding fixtures for articles to be cut, and more particularly tofixtures movable relative to cutting members for holding articles at given angular positions while being cut.

In the manufacture of synthetic crystals produced, for example, from ethylene diamine tartrate solutions, an endless string commercially identified as a string saw traveling through a fluid such as water which is a solvent for the synthetic crystal cuts or dissolves a path through the crystal. In this manner, by theme of a plurality of endless strings the synthetic'crystals may be divided into a plurality of wafer-like portions of equal thickness. The synthetic crystal similar to the quartz crystal, has certain inherent axes and the Wafer-like portions which are to'be embodied in electrical units of the communication arts must be cut or produced from the virgin crystal so that their faces will be at given angles with respect to certain of the axes in the crystal. Owing to the fact that the synthetic crystals are substantially identical in structure and that the said axes are in substantially the same positions in each crystal, movement of the article or syn- An object of the invention is to provide a holding fixture for an article, such as a crystal, to be cut into portions of given thicknesses, the portions extending at given angles with respect to the natural faces thereof. The natural faces are approximately aligned with the atomic planes of These natural faces may hence be used to align the crystal for producing cuts having any desired angular relation to the atomic planes and crystal axes. The crystal axes are themselves characteristic of the particular crystalline material.

With this and other objects in view, the invention comprises a holding fixture for the article or the crystal to be cut by a cutting member,

porting elements, and means to support the elev ments at fixed spaced positions relative to each other whereby relative movement of the fixture .and a cutting member will cause cutting of a path through the crystal by the cutting member at given angles relative to the atomic planes of Claims. (Cl. 125-35) the crystal as controlled by supporting it inthe grooves of the supporting elements.

More specifically, the article in the present embodiment of the invention is a synthetic crystal of ethylene diamine tartrate to be cut into wafers of given thicknesses by the aid of a pluralityof endless strands moving continually through a. solution such as water, to dissolve parallel paths through the crystal. To cut the wafers at the desired angles with respect to the atomic planes of the crystal, and to provide guidesv for the strands, the fixture includes a plurality of parallel plate-like elements secured together at one end. The other ends of the elements may be held in their proper positions by a retaining member removably secured in place. The supporting elements have aligned substantially V-shaped grooves therein cooperating to form a supporting groove in the fixture extending diagonally at a given angle across the paths of the cutting members or endless strands and to tilt the article at another given angle with respect to the parallel planes of the supporting elements.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawings wherein,

Fig. '1 is a side elevational view of a crystal cutting unit embodying the holding fixture;

Fig. 2 is a top plan view of the crystal partially Fig. 3 is a top plan view of the crystal-holding fixture illustrating the position of the partially cut crystal therein, taken as indicated by line 3-3 of Fig. 1;

Fig. 4 is a vertical sectional view of a fixture taken along the line l4 of Fig. 3; and

Fig. 5 is a fragmentary side elevational View of one of the supporting elements illustrating-the contour of the groove therein.

Referring now to the drawings, attention is first directed to Figs. 3 and 4 which illustrate the of the side members have aligned notches. l8

therein to receive reduced portions l9 of r oves '28.

bersf 3 screws 20. The thumb screws have their threaded portions 2| positioned in threaded apertures 22 in the opposite ends of a retaining member 23, the inner surface of which has a plurality of equally spaced notches 24 therein to receive the adjacent ends of the supporting elements Hi to hold them in their proper positions. 7 The retaining member may be readily removed from the supporting elements and the notches 18 of the side members II and 12 by loosening the thumb screws 20 and pulling the retaining member 23'- outwardly, making it possible to remove the fix-- ture from the cutting apparatus indicated generally at 25 in Fig. 1.

The supporting elements l5 havelike grooves 28 formed therein, as illustrated in Fig. 5, 06- operating to produce an article receiving groove in the top of the fixture which extends diagonally across the paths which will be out through the article determined by the spaces between the supporting elements, and which will support the article at a given angle with respect to the parallel'supporting elements. In Fig. 5 it will be noted. 'that one side" 30 of the groove is spaced from the other side 3| thereof by an inwardly cut portion- 32 at the juncture of the surfaces to re- 'ceive the lowermost edge of the article 33 where- 'by surfaces 34 and 35 of the article may rest upon their respective surfaces 30 and 3! of the Although the supporting elements are defined as having like grooves 28 formed thereon, only portions of these grooves are formed in certain of the supporting elements as shown in Fig. 3.

[The article" 33 in the present embodiment of the invention is a synthetic crystal formed from a solution of ethylene diamine tartrate. It will be noted thatthe cross-sectional contour of the crystal 33 is not truly rectangular and it has been found in the production or growing of these crystals that they assume this contour. Al-- though some crystals may be larger than others, depending upon the interval of time allowed for growing the crystals from their initial seeds in the aforementioned solution, the angular relations 'of'their sides with respect to their top and bottom surfaces remain the same. The contour of the groove 28 is such that regardless of variations in the width and thickness of successive articles or crystals, their faces or surfaces will be positioned at given angles with respect to the path of movement of the fixture relative to the cutting members and also relative to the planes of the supporting elements l5.

served that the groove 28 continues not only through the supporting elements IE but through It will be obthe side member II and spacing members 16 as illustrated in Fig. 3.

'In Fig. 1 the fixture is shown in combination with a cutting apparatus 25 which includes grooved rollers 38, 39, 40 and 4| to receive a plurality of cutting members 42 which in the present' embodiment are endless strand-like mem- The cutting members 42 in traveling in their guided paths about the rollers, driven by the rotation of the roller 38 through suitable means '(not shown), travel into a liquid or solution 45 to become saturated therewith. The

' liquid 45 in the present embodiment of the invention is water, maintained at a given level,

whereby the cutting members will be submerged therein during their travel about the rollers. The

' temperature of the water may be controlled withment with the shaft '49.

tals into'portions of equal thicknesses.

havingranoily constituent could not be used,

since it would clog the string and prevent proper cutting action.

The fixture or the carriage l0 thereof is 'rnounted 'for longitudinal movement On parallel bars '46-by the aid of grooved guide blocks 4'! mounted on the under surfaces of the carriage. The "means for moving the fixture relative to the cutting members 42 .includes a threaded shaft =49. m'ountediin 'suitablezbearings' 59 and rotated a: given direction at a predetermined speed by suitable; ;means (not shown) A threaded segme'nt 5l' supported by' an arm 52 ispivotally secured to the carriage for removable connection withrthe threaded shaft 49 to cause movement of the fixture relative to the cutting members duringrotation of the -threadedshaft.

' Whenthe' fixture is to be employed for cutting: the articles or crystals 33, it is placed upon :the parallel bars 46-with the retaining member =23*removed and thesegment 5| out of engage- The' fixture is then moved-to cause theleading ends of the supportingelements I5 tomove beyond the cutting members-T42 causingthem to enter the guideways between the supporting elements. ing' mem'ber 23 isthen inserted in place withithe leadingends of the supporting members enteringtheirrespective notches 24 and by this means,

The retainthefree ends of the supporting elements are firmly held in their respective equally spaced parallel positions by tightening the thumb'screws v20rto-rigidly secure the retaining member in place.

The fixture is now in position for repeated operations in cutting the synthetic crys- The crystal is placed in the groove 28 so that the surfaces 34 and 35 will rest on theirrespective surfaces 30 and 3| of the supporting elements after which the member 5| is moved into engagement -with the threaded shaft '49. The fixture will be moved to the'right at a given speed, causing :the cuttingmembers 42'to cut'their individual paths through the crystal, eventually cuttingthecrys- 'tal into a plurality of parts of equal thicknesses, "which parts originally assumed given angular positions in the crystal.

*After one crystal has-been cut 'into a given number of parts, these parts may be removed from the fixture. The fixture may then" be returned to its starting position after disconnectingthe member 5! from the threaded shaft. The fixture is now in position for the cutting of 'another' crystal or article. All that is required is the placing of the crystal in the proper position inthe groove '28 and again connecting the mem-- -ber 5 ltothe threaded shaft.

It is to be understood thatthe above described arrangements are simply illustrative of the application of the principles of the invention. Numer- 0115 other arrangements may be readilydevised bythose'sk'illed in'the art which will embody the principles of the invention and fall within the spirit and scopethereof.

What is claimed is:

1. A holding fixture for a crystal to be cut into portions of given thicknesses by traversable cutting member, comprising a plurality of parallel supporting elements, means disposed terminally of said elements to maintain fixed spaced positions therebetween, and a groove formed in and extending across said spaced parallel supporting members shaped to constitute a crystal seat which will present said crystal to said cutting member in such a, position that portions cut therefrom during traverse of said crys tal relative to said cutting member will have desired angular orientations relative to the atomic planes of said crystal.

2. A holding fixture for a crystal to be cut into portions of given thicknesses by a plurality of cutting members, comprising a plurality of parallel supporting elements having grooves formed therein and aligned to define surfaces adapted to support said crystal with a desired orientation and means disposed terminally of said elements to maintain fixed spaced relations therebetween whereby relative movement of said fixture relative to said cutting members will permit production of crystal portions having a desired orientation relative to the atomic planes of said crystals.

3. A holding fixture for a crystal to be cut into portions of given thicknesses by a cutting member, comprising a unit supported for movement in a given path relative to said cutting member and comprising supporting elements having a plurality of spaces therebetween parallel with the said path and in alignment with said cutting member, said supporting elements also having aligned V-shaped notches to receive and support said crystal in a given angular position relative to the said path whereby said crystal will be cut at a given angular position and orientation relative to the crystalline axes thereof by said cutting member during movement of said unit relative thereto.

4. A holding fixture for an article having inherent crystalline axes to be cut into portions of given thicknesses by a, cutting member to be directed at given angles through said article relative to said axes comprising a unit supported for movement in a given path relative to said cutting member and comprising supporting elements having a plurality of spaces therebetween parallel with the said path and in alignment with said path and said cutting member, and notched portions formed in said supporting elements and aligned to form grooves extending transversely of the said path to receive and support said article in given angular positions relative to the said path, whereby the said article will be cut at a given angular position and orientation relative to the crystalline axes thereof by said cutting member during movement of said unit relative thereto.

5. In combination with a string saw having a plurality of parallel string members and a table traversable relative thereto, means for holding crystals to be cut, comprising a plurality of spaced parallel supporting plates arranged to act as guides for the passage of said string members; means, removable to permit terminal entry of said string members between said plates, for rigidly maintaining parallel alignment of said plates; and seat portions so formed in said plates as to present said crystal to said string members rotated degrees about the X axis and 27 degrees to the direction of traverse of said crystal relative to said string saw.

WALTER L. BOND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,144,370 Gerlach Jan. 17, 1939 2,361,961 Pruitt Nov. 7, 1944 2,431,469 Eyles .Nov. 25, 1947 

